Incidence of carcinoma in situ of germ cells in contralateral testis of men with testicular tumours

Contralateral biopsies in patients with testicular germ cell tumours: What is the rationale?

INTRODUCTION

In 1979, the Copenhagen group around Dr. Skakkebaek introduced contralateral biopsy in patients with testicular germ cell tumour (GCT) as a means of early diagnosing a contralateral testicular tumour (Berthelsen et al. in Br Med J 2(6186):363-364, 1). Although the rationale of contralateral biopsies is based on much of scientific evidence, no issue regarding the management of GCTs has been more controversial than the issue of contralateral biopsies (Heidenreich in BJU Int 104(9 Pt B):1346-1350, 2; Grigor and Rorth in Eur Urol 23(1):129-135, 3). A poll conducted during the GCT Consensus Meeting in Berlin 2011 revealed that 43 % of 60 leading experts would not recommend a contralateral biopsy and only 13.7 % would do the biopsy in all cases with GCT (Beyer et al. in Ann Oncol 24(4):878-888, 4). Likewise, the European Association of Urology and the European Society of Medical Oncology offer only weak recommendations with respect to contralateral biopsies in their guidelines of testicular cancer (Albers et al. in Eur Urol 68(6):1054-1068, 5; Oldenburg et al. in Ann Oncol 24(Suppl 6):vi125-vi132, 6).

CONCLUSION

This review summarizes contemporary knowledge regarding contralateral biopsies to provide professionals caring for GCT patients with sufficient information to decide for or against the procedure in clinical practice.

Perspectives in Pediatric Pathology, Chapter 14. Natural History of Undescended Testes

Cryptorchidism is one of the most frequent problems encountered in pediatric urology. Its causes, associated lesions, and prognosis in terms of fertility have been a source of interest and discrepancies for pediatric pathologists and urological surgeons.

Evidence that active demethylation mechanisms maintain the genome of carcinoma in situ cells hypomethylated in the adult testis

BACKGROUND

Developmental arrest of fetal germ cells may lead to neoplastic transformation and formation of germ cell tumours via carcinoma in situ (CIS) cells. Normal fetal germ cell development requires complete erasure and re-establishment of DNA methylation. In contrast to normal spermatogonia, the genome of CIS cells remains unmethylated in the adult testis. We here investigated the possible active and passive pathways that can sustain the CIS genome hypomethylated in the adult testis.

METHODS

The levels of 5-methyl-cytosine (5mC) and 5-hydroxy-methyl-cytosine (5hmC) in DNA from micro-dissected CIS cells were assessed by quantitative measurements. The expression of TET1, TET2, APOBEC1, MBD4, APEX1, PARP1, DNMT1, DNMT3A, DNMT3B and DNMT3L in adult testis specimens with CIS and in human fetal testis was investigated by immunohistochemistry and immunofluorescence.

RESULTS

DNA from micro-dissected CIS cells contained very low levels of 5hmC produced by ten eleven translocation (TET) enzymes. CIS cells and fetal germ cells expressed the suggested initiator of active demethylation, APOBEC1, and the base excision repair proteins MBD4, APEX1 and PARP1, whereas TETs - the alternative initiators were absent. Both maintenance and de novo methyltransferases were detected in CIS cells.

CONCLUSION

The data are consistent with the presence of an active DNA de-methylation pathway in CIS cells. The hypomethylated genome of CIS cells may contribute to phenotypic plasticity and invasive capabilities of this testicular cancer precursor.

Management of the contralateral testicle in patients with unilateral testicular cancer

Patients with a prior history of a germ cell tumor of the testicle are known to have an increased risk of development of a second germ cell tumor in the contralateral testicle. It is believed that all patients who develop a germ cell tumor of the testicle have a precursor lesion know as carcinoma in situ (CIS) or intratubular germ cell neoplasia. Approximately 50% of these patients will subsequently go on to develop a germ cell tumor in the testicle. A biopsy of the contralateral testicle in a patient with a previous history of a germ cell tumor of the testicle has been advocated by some, while others recommend a biopsy only in patients with other risk factors as well. The arguments for biopsy are that intervention may be used to prevent the development of a second germ cell tumor when CIS is detected. In this review we present the arguments for and against a biopsy of the contralateral testicle, review the techniques of biopsy as well as its complications, and discuss the interventions employed to prevent CIS from progressing.

Diagnosis and management of testicular intraepithelial neoplasia (carcinoma in situ)--surgical aspects

Germ cell tumours (CT) are no true carcinomas; therefore the term testicular intraepithelial neoplasia (IN) is probably more appropriate than "CIS". The diagnostic accuracy of a single-site biopsy is an open question. We experienced 9 false-negative biopsies among 1859 cases. Thus, the proportion of a failed diagnosis is 0.5%. The main reason for diagnostic failure is the non-random distribution of TIN within the testicle. Currently we are investigating whether a two-site biopsy is more accurate than a single biopsy. In the ongoing trial, the over-all prevalence of TIN is around 5.3%, so far. In one quarter of the positive cases the lesion was found in only one of the two specimens. Thus, a double biopsy appears to be more favourable than the traditional single biopsy. Surgical complications amount to 2.5% in that double biopsy study. Only one surgical re-intervention was required among 983 patients. Serial imaging studies with scrotal sonography and magnetic resonance imaging (MRI) disclosed a transient intratesticular haematoma/oedema postoperatively. So, testicular biopsy, even when performed at two sites is in fact a low-complication procedure. Low dose radiotherapy to the testis is the treatment of choice for TIN. However, more than one quarter of patients require testosterone supplementation secondary to androgen-deficiency. Two dose-reduction studies (Denmark and Germany) had to be terminated prematurely because unexpected relapse of TIN was encountered at 14 Gy and 16 Gy. Possibly, hyperfragmentation schedules can overcome the antagonism of androgenic compromise and oncological safety. In a nation-wide survey, it was shown that contralateral biopsies were routinely performed in 66% of the urological departments in Germany. Another 19% offered the biopsy to particular "risk-cases"; only 15% never did a biopsy. Among those refusing biopsies, there was a higher proportion of small hospitals and a significantly lower annual case-number of GCT, when compared to those doing the biopsy. Thus, the contralateral biopsy is a well-established procedure among German urologists; those with a high caseload of GCT particularly appreciate it.

Long-term outcomes of elective human sperm cryostorage

BACKGROUND

Sperm cryopreservation allows men with threatened fertility to preserve their progenitive potential, but there is little data on long-term outcomes of elective sperm cryostorage programmes.

METHODS AND RESULTS

Over 22 years, 930 men sought semen cryostorage in a single academic hospital, of which 833 (90%) had spermatozoa cryostored. Among 692 (74%) men surviving their illness, sperm samples were discarded for 193 (21% of all applicants, 28% of survivors) and cryostored spermatozoa were used for 64 men (7% of all applicants, 9% of survivors) in 85 treatment cycles commencing at a median of 36 months post-storage (range 12-180 months) with nearly 90% of usage started within 10 years of storage and none after 15 years. Pregnancy was most efficiently produced by intracytoplasmic sperm injection (median three cycles) compared with conventional IVF (median eight cycles) or artificial insemination (median more than six cycles; P < 0.05). A total of 141 (15%) of men had died and of these, 120 (85% of those dying) had their spermatozoa discarded; requests to prolong cryostorage were received from relatives of 21 men (2% of all applicants, 15% of deceased) of which three cases had spermatozoa transferred for use with no pregnancies reported. Sperm concentration was lower for all cryostorage groups compared with healthy sperm donor controls (P < 0.05). Following orchidectomy, men with testicular cancer had sperm density approximately half that of all other groups of men seeking cryostorage (P < 0.05), the lowering attributable to removal of one testis rather than in defects in spermatogenesis.

CONCLUSION

Elective sperm cryopreservation is an effective, if sparsely used, form of fertility insurance for men whose fertility is threatened by medical treatment and is an essential part of any comprehensive cancer care programme.

Carcinoma in situ of the testis: review of biological and clinical features

Carcinoma in situ of the testis (CIS) is the uniform precursor of testicular germ-cell tumours. Morphologically, CIS consists of large, intratubular, gonocyte-like cells with large nuclei and abundant glycogen. CIS cells are probably derived from primordial germ cells and are supposed to be present in the testis of a future testis cancer patient at the time of birth. CIS cells appear to spread inside the seminiferous tubules until CIS progresses to invasive cancer. Diagnosis is best achieved by surgical biopsy of the testis and subsequent immunohistological staining of placental alkaline phosphatase (PlAP). This enzyme is present in embryonal germ cells, CIS and seminoma as well as several other types of germ-cell tumour but usually not in normal germ cells. CIS is found in testicular tissue adjacent to testicular germ-cell tumours in about 90% of cases, and it is observed in all clinical groups known to be at risk for testicular cancer: cryptorchidism (2% to 4%), infertility (0% to 1%), ambiguous genitalia (25%) and contralateral testis of patients with testicular cancer (5%). Conversely, CIS is found in less than 1% of the normal male population, and this prevalence corresponds well to the life-time risk of testicular cancer in males. If CIS is left untreated, there is a 50% probability of progressing to frank germ-cell neoplasm within 5 years. Localised low-dose radiotherapy to the testis eradicates CIS and germ cells, while Leydig cells are preserved. The patient can thus be spared orchiectomy and hormone supplementation. Currently, dose-reduction studies are looking for the optimal radiation dose, which is expected to be around 14 to 16 Gy. After chemotherapy, there is a cumulative risk of 42% for recurrence of CIS within 10 years. The concept of CIS offers the chance of very early detection of testicular cancer and organ-preserving early treatment.

Germ cell cancer and disorders of spermatogenesis: an environmental connection?

Why is there a small peak of germ cell tumours in the postnatal period and a major peak in young age, starting at puberty? And, paradoxically, small risk in old age, although spermatogenesis is a lifelong process? Why is this type of cancer more common in individuals with maldeveloped gonads, including undescended testis, gonadal dysgenesis and androgen insensitivity syndrome? Why has there, during the past 50 years, been a quite dramatic increase in testicular cancer in many developed countries? These are just a few of many questions concerning testicular cancer. However, the recent progress in research in the early stages of testicular cancer (carcinoma in situ testis (CIS)) allows us to begin to answer some of these questions. There is more and more evidence that the CIS cell is a gonocyte with stem cell potential, which explains why an adult man can develop a non-seminoma, which is a neoplastic caricature of embryonic growth. We consider the possibility that CIS cells may loose their stem cell potential with ageing. Along these lines, a seminoma is regarded a gonocytoma where the single gonocytes have little or no stem cell potential. The Sertoli and Leydig cells, which are activated postnatally and during and after puberty, may play a crucial role for both the development of the CIS gonocyte and progression of the neoplasm to invasiveness. The reported increase in testicular cancer is not the only sign that male reproductive health is at risk. There are reports that undescended testis and hypospadias have become more common. Also semen quality has deteriorated, at least in some countries. The epidemiological evidence suggests that environmental factors may play a role. Are the environmental hormone disrupters (e.g. DDT, PCB, nonylphenol, bisphenol A) to be blamed for the apparently synchronised deterioration in these aspects of male reproductive health?

Prevalence of bilateral testicular germ cell tumours and early detection based on contralateral testicular intra-epithelial neoplasia

The prevalence of bilateral tumours was found to be 4% in a retrospective analysis of 531 consecutive patients with testicular germ cell tumours. Patients with bilateral tumours were younger when their first tumour was diagnosed than those who had only 1 testicular tumour. Bilateral undescended testis was more frequent in 21 patients with bilateral tumours than in the total population of patients examined (2 of 21 versus 10 of 452, i.e. 9.5% versus 2.2%). Histology and unilateral undescended testis were not helpful in identifying patients at risk of developing a second tumour. In a separate study, 76 consecutive patients with unilateral testicular cancer underwent contralateral testicular biopsy at the time of orchiectomy. Five patients had testicular intra-epithelial neoplasia (TIN, so-called carcinoma in situ) in the contralateral testis; 1 of these patients had a history of bilateral undescended testis and 4 had an increased level of serum follicle stimulating hormone post-operatively. None of the other 71 patients had developed a second tumour after a median observation time of 30 months. Testicular biopsy and a search for TIN appear to be a safe method for the early identification of the patients at risk of developing a contralateral testicular tumour.

Laterality, maldescent, trauma and other clinical factors in the epidemiology of testis cancer in Victoria, Australia

Clinical factors were studied in a population based survey of 1,116 cases of testicular neoplasms in Victoria, Australia, between 1950 and 1978. The ratio of right to left sided tumours was 54:46, but the left side predominated among sarcomas (P = 0.006), and in older men. The relative risk (RR) for men with unilateral maldescent was 15 (CI 10-23) and for men with bilateral maldescent 33 (CI 20-55) (odds ratio 1.4, CI 0.5-4, P = 0.7). Calculations per testis in men with unilateral maldescent showed an elevated risk for both the maldescended testis (RR 28, CI 19-41, P less than 0.0001) and the normally descended testis (RR 3, CI 1.2-6, P = 0.04). The RR for men with abdominal maldescent was 55 (CI 36-83) compared to 7 (CI 4-11) for those with inguinal maldescent (odds ratio 8, CI 3-20, P less than 0.0001). Seminomas were more common than nonseminomas (NSGCT) in men with a history of maldescent (odds ratio 1.7, CI 1.1-3, P = 0.02) and also among corrected cryptorchids compared to uncorrected (P = 0.005). Seminomas were diagnosed at an earlier median age in men with corrected cryptorchid testes compared to uncorrected (P = 0.03) and in men with corrected cryptorchid testes compared to normally descended (P = 0.001). Maldescent was also associated with hernia (P = 0.04). Twenty-eight per cent of patients recorded a history of trauma with a higher proportion among NSGCT than among seminomas (P = 0.03). Prior malignancies were reported in nine patients, compared to 3.6 expected; prostate cancer (2) and malignant melanoma (2) were the greatest contributors to the excess.

Effects of chemotherapy on fertility

Over recent years radical improvements in the treatment of malignant disease have resulted in the cure of patients in or approaching reproductive age, and with that cure, the effects on gonadal function have become apparent. Gonadal failure is particularly important in Hodgkin's disease, germ cell tumours, choriocarcinoma, and leukaemia, diseases of young people which are largely curable. Premature ovarian and testicular failure are easily missed by doctors concerned primarily with the erradication or arrest of a life-threatening disease, but for the patient the hormonal, psychological and social sequelae of treatment may be devastating. In this article we review the effects of chemotherapy on gonadal function and discuss the management of gonadal failure.

Testicular carcinoma in situ and nonpalpable seminoma eight years after contralateral teratocarcinoma

A thirty-five-year-old man had invasive seminoma and extensive carcinoma in situ in his remaining testicle eight years after orchiectomy and lymphadenectomy for Stage I teratocarcinoma. Beyond orchiectomy and hormone replacement, suitable treatment for such second neoplasms, which occur in at least 1 percent of patients, is not clear. More work also is needed to determine appropriate follow-up after treatment of the first cancer now that long-term survival of testicular cancer is the rule.

Carcinoma in situ of the testes: diagnosis by aspiration flow cytometry

Carcinoma in situ of the testes has been described as a premalignant state with the potential to progress to invasive carcinoma. A history of testicular carcinoma, cryptorchidism, somatosexual ambiguity and infertility has been identified as a risk factor for carcinoma in situ. A series of 25 infertility patients underwent aspiration biopsy of the testis as part of a study protocol to assess spermatogenesis. Of these patients 1 had a unilateral seminoma. In accordance with the study protocol the contralateral testis was aspirated at radical orchiectomy and the deoxyribonucleic acid histogram generated demonstrated an aneuploid peak. Carcinoma in situ subsequently was noted on tissue biopsy. The discovery of carcinoma in situ cells in this manner highlights the potential of this technique as a diagnostic tool for the screening and followup of men at increased risk for carcinoma in situ.

Carcinoma in situ of the testis in infertile men. A histological, immunocytochemical, and cytophotometric study of DNA content

Of 723 infertile men (128 with a history of cryptorchidism) whose testes were biopsied at the outer lateral face of the testis, five presented carcinoma in situ (CIS) in one testis. These testes were removed, serially sectioned, and examined by light microscopy. In order to evaluate whether only one or two biopsies are sufficient to diagnose CIS, before sectioning the testes four biopsies were taken at the anterior face, posterior face, superior pole, and inferior pole of the testis, respectively. Two of the five men had undergone orchiopexy in infancy and the testis contained tubules with Sertoli cells and isolated spermatogonia. CIS was also present in some tubules that were principally located near the rete testis. Of the four simulated biopsies, only that performed at the posterior face of the testis revealed CIS. The other three infertile men showed tubules with complete, although reduced, spermatogenesis, and tubules lined by Sertoli cells only. CIS was found in both types of tubules. These tubules with CIS formed lobules that extended throughout the testicular parenchyma. Most simulated biopsies performed in these three testes showed CIS. The average nuclear DNA content of CIS cells was about 4c in all testes. This content was similar both in tubules with complete spermatogenesis and in tubules with Sertoli cells only.

Carcinoma in situ in testicular biopsies

Carcinoma in situ of the testis is an abnormality of the seminiferous epithelium characterized by aneuploid cells with clear cytoplasm located along the tubular basement membrane or in the lumina of tubules. Morphological, cytogenetic, and histochemical features of this anomaly are presented. An adequate fixation of testicular tissue samples is necessary for correct diagnosis. The fact that approximately 50% of carcinoma in situ may develop into malignant germ cell tumours of the testis in 5 years and the investigations of the testicular tissue adjacent to these tumours support the malignant nature and invasive potential of testicular carcinoma in situ. The incidence of carcinoma in situ in persons at risk is reviewed.

Germ cell function and hormonal status in patients with testicular cancer

Sperm counts, serum gonadotropins, and androgen levels were investigated in 39 seminoma patients and 58 patients with a nonseminomatous germ cell tumor of the testis after unilateral orchiectomy. In 58% of the patients, the total sperm count was below the lower reference value (80 million). A multiregression analysis demonstrated a correlation between a decreased total sperm count and the following three explanatory variables: (1) an elevated serum alpha-fetoprotein (AFP), (2) a history of chryptorchidism, or (3) a seminomatous tumor. In 42% of the patients, the sperm concentration and the sperm motility met criteria considered sufficient for cryopreservation. Serum follicle-stimulating hormone (FSH) was elevated in 33% of the patients. Androgens (serum testosterone [T] or urine 17-oxy-steroids [17-OS]) were subnormal in 5% of the patients, whereas serum luteinizing hormone (LH) was elevated in 14% of the patients without human chorionic gonadotropin beta-subunit (beta-HCG) in serum.

Synchronous bilateral primary germ cell tumors in patient receiving estrogen therapy

The present report concerns the occurrence of bilateral synchronous germ cell tumors in a sixty-eight-year-old man who received estrogen therapy for eleven months. Although there are previous reports on Leydig cell tumors developing in mice and man receiving estrogens, we have not found any connection between germ cell tumors and estrogen medication reported in the literature.

Synchronous bilateral testicular tumors of different cell types on each side

Bilateral and synchronous testicular tumors consisting of different cell types on each side are rare. We describe one additional case of synchronous bilateral testicular tumors comprised of different cell types on each side and review the relative literature.

Management of carcinoma-in-situ of the testis

Carcinoma-in-situ (CIS) of the testis progresses to invasive cancer within 5 years in 50% of cases, and therefore requires therapeutic intervention. CIS is probably eradicated by intensive cancer chemotherapy but this is too toxic for the management of non-invasive disease. Eight patients with unilateral testicular cancer and contralateral CIS received localized irradiation (20 Gy in ten fractions of 2 Gy) to the remaining testis: after 3 months the CIS cells had disappeared and 'Sertoli-cell-only' tubules were found. LH and FSH levels were elevated but testosterone levels remained fairly constant. Localized irradiation should be considered as the treatment of CIS in the contralateral testis of testicular tumour patients unless chemotherapy is indicated for the primary tumour. Unilateral orchidectomy is recommended for unilateral CIS associated with infertility or testicular maldescent. Localized testicular irradiation should now be considered for bilateral disease. Patients with the androgen insensitivity syndrome should normally be treated with bilateral orchidectomy, but irradiation may be useful in selected cases.

Testicular germ cell tumors after clomiphene therapy for subfertility

The stimulatory effect of low doses of clomiphene citrate on the human male gonad is accepted widely. We used 25 mg. clomiphene daily for 3 weeks, with 1 week of rest, for 6 to 12 months in 650 oligospermic men without increased serum levels of follicle-stimulating hormone (less than 20 IU/l.). Unilateral testicular neoplasm developed in 2 subjects. Although a definite cause-and-effect relationship between treatment and tumor development cannot be assigned the possible risk of tumor development in men undergoing long-term clomiphene treatment is suggested. Since clomiphene administration or gonadotropin treatment might enhance tumor development in men, patients at risk undergoing such therapy should be examined frequently and when a testicle enlarges a malignant tumor must be ruled out.

Testicular germ cell tumours. Current problems of histogenesis and classification

Testicular germ cell tumours, owing to their variety in biological behaviour and morphological appearance, claim a place of their own in clinical oncology and tumour research. Much of the histogenesis has remained unexplained, as reflected by the different systems of pathological classification. This report sums up, on basis of the literature, the current pathologic views on the question of testicular tumour genesis. Data obtained from immune histochemical examinations, animal experiments, ultrastructure studies, together with clinical observations, suggest that differentiation of the carcinomatous stem cells are apt to produce forms, transitional between seminomatous and non-seminomatous types of tumour. The possibility to set up a uniform, clinically appropriate nomenclature depends on the progress in histogenetic knowledge.

Atypical germ cells of the testis. Comparative ultrastructural and immunohistochemical investigations

It is uncertain whether the so called intratubular atypical germ cells (carcinoma in situ cells) demonstrable in the testicular tissue around different germ cell tumors and in testicular biopsies of patients with impaired fertility are identical with regard to their morphology and further development. Thus atypical germ cells of 18 patients with testicular germ cell tumors and of 3 patients with atypical germ cells in testicular biopsies without tumor were studied by electron microscopy and/or by immunohistochemistry. The atypical germ cells show characteristic alterations distinguishing them from normal germ cells, especially spermatogonia. However, there are no differences between atypical germ cells in the above mentioned groups. Immunohistochemical reactions are negative with anti-alpha-fetoprotein and anti-beta-human-chorionic-gonadotropin, but 6 of the 15 cases are positive with antiferritin. However, this positive reaction occurs in cases in different diagnostic groups. Atypical germ cells of the different groups cannot be distinguished by electron microscopy or immunohistochemical methods, but further investigations, including cell cultures, may provide more information.

Carcinoma in situ of germ cells and subsequent development of an invasive seminoma in a hyperprolactinaemic man

A 25-year-old man was first seen complaining of impotence and found to have a pituitary tumour and hyperprolactinaemia. Both testes were small and atrophic, but a testicular tumour was not apparent. Biopsy of the right testis was performed, and the pathology report described thickening of the seminiferous tubule walls and impaired spermatogenesis. The patient refused to undergo an operation for his pituitary tumour and was lost to follow-up. 5 years later, the same patient presented with enlargement of his right testis, and this and the pituitary tumour were excised. The testicular tumour was classified as seminoma, and the pituitary tumour as an adenoma with low malignancy. Re-examination of the previous specimen of his right testis revealed foci of carcinoma-in-situ. This is an additional example of the growth of an invasive germ cell tumour from non-invasive carcinoma-in-situ of the testis.

Synchronous bilateral primary germ cell tumors of the testis: a case report and review of the literature

Synchronous bilateral primary germ cell tumors of the testis are exceedingly rare. The most common synchronous testicular tumors are seminomas, followed by embryonal carcinomas, teratocarcinomas, and choriocarcinomas. In a series of 385 patients we found nine with bilateral primary germ cell tumors of the testis (2.3%), including one with synchronous involvement of both testes. The treatment of synchronous bilateral primary germ cell tumors of the testis is in principle the same as that of solitary testicular primary germ cell tumors, and is based on tumor histology and tumor metastasis.

Screening for carcinoma in situ of the contralateral testis in patients with germinal testicular cancer

Two hundred and fifty biopsy specimens from the contralateral testis in patients with unilateral germinal testicular cancer were analysed by light microscopy for carcinoma-in-situ changes. Changes were found in 13 (5.2%) patients. One-third of patients with an atrophic contralateral testis (volume less than or equal to 12 ml) and one-fifth of patients with a history of cryptorchidism had changes in the remaining testis. In the present series 85% of cases with carcinoma-in-situ changes would have been diagnosed if the one-fifth of the patients having an atrophic testis or a history of cryptorchidism or both had been screened. Since the natural course of carcinoma in situ in the contralateral testis of patients with germinal testicular cancer has not been established, the patients are being re-evaluated frequently. To date two patients with carcinoma in situ have developed a second cancer.

Sequential bilateral germ cell testicular tumors of different cell types

A case of bilateral successive testicular cancer of different cell types (seminoma and embryonal carcinoma) is presented. The time interval between the two tumors was 30 months. Previous reports in English of bilateral testicular tumors are briefly reviewed.

Value of testicular biopsy in diagnosing carcinoma in situ testis

Quantitative histological studies on four testicles removed because of carcinoma in situ (CIS) were performed in order to determine the likelihood of diagnosing carcinoma in situ testis by biopsy. The CIS changes were evenly distributed in the testicles except for the parts adjacent to the epididymis, where the lesion was less frequent. In parts of the testicles where more than approximately 10% of the testicular volume contained tubules with CIS all simulated biopsies measuring 3 mm contained the lesion. The same was true for simulated biopsies measuring 1.5 mm when more than approximately 30% of testicular volume consisted of tubules with CIS. If the distribution of carcinoma in situ generally is similar to that found in the four analysed testicles there seems to be a high probability of detecting the disease by one or two testicular biopsies of 3 mm.